Distant galaxies are normally difficult to see, but those whose
dim light are shrouded in dust are especially difficult to
detect, even using the largest available telescopes. However,
astronomers are able to essentially boost the effectiveness of
their telescopes by
relying on lenses of a sort massive galaxies or clusters of
galaxies between the astronomers and the objects they want to
look at.

The gravitational pull of massive intervening objects distorts
space-time, an effect that can deflect light. This " gravitational
lensing " can increase the visibility of the distant galaxies
or possibly lead researchers to seeing multiple images of them.

Typically, finding gravitational lenses is very time-consuming.
Now, using data from the
Herschel Space Telescope, a large, international research
team has found that gravitationally lensed galaxies can be
detected easily in submillimeter wavelengths of light if a
sufficiently wide area of the sky is searched.

The objects seen in the submillimeter range are generally thought
to be distant, dusty galaxies undergoing a vigorous burst of star
formation. This intense activity generates the dust that obscures
them. In a wedge of sky that researchers analyzed, they
discovered what appears to be five new gravitationally lensed,
dusty star-forming galaxies.

"I was predicting about four to six of these sources to be
detected in our first data collected one year ago," said
researcher Mattia Negrello, an astronomer and cosmologist at The
Open University in Milton Keynes, England. "Those data
corresponded to about 3 percent of the total area that will be
mapped by Herschel within the H-ATLAS (Herschel Astrophysical
Terahertz Large Area Survey). You can imagine how excited I was
when we discovered exactly five."

They observed the sky for submillimeter radiation, identified the
brightest objects and removed a few "contaminants" such as nearby
galaxies. Everything that was left turned out to be the
star-forming galaxies. "This is arguably the easiest way to
spot gravitational lensing events ever conceived," Negrello said.

The five galaxies the researchers found are just the tip of the
iceberg, Negrello told SPACE.com. "We expect to discover more
than 100 of them in the full H-ATLAS," he said. By capturing
details amplified by gravitational lensing on
large numbers of these galaxies, the scientists hope to
better understand how they formed and evolved.

The scientists detailed their findings in the Nov. 5 issue of the
journal Science.